Method of protecting metal bodies from corrosive agencies



Patented Sept. 30, 1930 UNITED STATES PATENT OFFICE PAUL I. SCHADE, OF BERLHU, GERMANY, ASSIGNOR TO CHEMIEPRO DUKTE G. M. B. E, OF BERLIN, GERMANY, A CORPORATION 01 GERMANY METHOD OF PROTECTING META]: BODIES FROM CORROSTVE AGENGIES llo Drawing. Application filed November 11, 1927, Serial Rio. 232,718, and in Germany July 27, 1927.

In spite of numerous attempts that have been made with the end in view of providing protection from corroding agents in a way that would beperfect and satisfactory in all 5 respects for all such metal bodies and parts as gas and water pipes, cables, and the like which are buried underground or laid in masonry, that is, placed in conditions where they are more or less exposed and subjected to the influence of humidity and gases, it may be said that the ways and means heretofore used in practice for the above purpose are attended with considerable disadvanta es.

n most cases protective substances in the form of a coat of lacquer or varnish or color are applied. 'But such coats become brittle after some time'and cracks are formed which unite and eventually result in a gradual scaling oil of the protective coat. Therefore the protection afforded by this sort of coatin is insuflicient, unreliable and unsafe. Ot er methods consist in first applying to the parts of pipes to be protected a dense layer of tar, after which the parts of the pipe thus pre-treated are wrapped with a tar-soaked strap or wrapper, and finally a second layer of tar is applied.

Quite apart from the lack of economy and the "expense of such a procedure in which heating of the tar for each application is absolutely necessary. in order to give it sufficient plasticity, the foregoing method which is generall practiced in connection with the laying 0 gas and water pipes and of cables has the additional great drawback that the tar, especially in the presence of relatively low temperatures, becomes brittle so that the ensuing cracks tend to increase not .only the permeability of the tar coats, but

also cause tearing of the wrapping layers so that after some time noreliable and safe protection of metal parts can be insured.

These disadvantages are completely overcome, by the present invention. By this invention the metal parts to be 'rotected are wrapped in situ before-being uried in the ground, with fabric or paper wrappers, the atter havin upon both faces coats of material that wi not become brittle or crack for years even under most unfavorable conditions.- The material remaining on the outside of the wrapper thus made is smoothed or rubbed so that a perfectly uniform closing of overlapping portions and joints is insured in order that the entrance of moisture ture which is particularly suited for carrying out this invention consists of proto-' parafiines having a melting point over 50 degrees 0., petroleum jellies with a melting point of around 20 degrees C. with an addition of soft bitumen having a melting point of around 30 degrees C., the balance of the mixture consisting of suitable finely ground fillers or loaders such as kaolin, tallow, heavy spar, porcelain clay, and thelike, When using the term proto-parafiine I desire of being understood that I mean to imply by this term the easily fusible constituents of the lubricating oils which constituents are gained from lubricating oils resulting from the mineral oils. Proto-parafiines have their melting points above 50 C. These fillers not only serve the purpose of enhancing the consistency of the mass, but they also safeguard the embedded metal parts, because of their excellent electric insulating powers, from the electrolytic actions due to stray ground currents of various origins upon the embedded metal parts. Y

The said mass or mixture is suitably made in such'a manner that the plastic materials required in the compound, either singly or combined, or mixed, areheated to over 100 degrees C. in order to thoroughly rid them of all traces of water. The filler is then added to the plastic mixture while it is bepound, say to 2030 degrees C., the same is applied 'upon the wrapper upon both faces thereof bya rolling process or in any other convenient well known manner.

The following example is given as a s ecific illustration of the invention, which as proved particularly satisfactory: A mixture consisting of about 30 parts by weight of proto-parafiin havin a melting point of about 60 degrees C. is eated together with 10 parts of petroleumjelly having a melting point of about 25 degrees C., and 5 parts of soft bitumen, having a melting point of I about 30 degrees 0., to a temperature around 15.

110 degrees C. until all traces of aqueous moisture'have been removed. Thereupon parts by weight of finely ground porcelain clay or kaolin are poured into the hot mass while it is stirred to insure uniform and thorough intermingling, this mixing ste being continued until the mass has coole down to a temperature of around 25 degrees C. When this point has been reached the mixture is applied to the wrapper, upori both faces thereof, in any convenlent 'way, and this finishes the process of preparing the protective means disclosed in this invention in a form ready for use at any desired time.

Of course, the mixing ratios may be varied within wide limits, without causing any appreciable impairment in the favorable actions of the wrapper, so far as insuring an absolutely safe protection from moisture, gases and electrolytic actions by parasitic currents in the ground is concerned. The filling or loading materials may be omitted in certain cases without serious detriment.

I claim:

1. The process of formin a permanently plastical protective coating or underground pipes and the like which comprises heating a mixture of plastic products having melt-v ing points between about 25 C. and 60 C. to a temperature above 100- C. and stirring the mixture. 1

2. The process of forming a permanently plastical (protective coating for underground pipes an the like which comprises heating a mixture of plastic products having mg points between about 25 C. and 60 C., that will not become brittle at 0 C., to a temperature above 100 C. and stirring the mixture.

3. The process of forming a permanently plastical protective coating for underground pipes and the like which comprises heating a mixture of plastic products having melting points between about 25C. and 60 C.,

that will not become brittle at'about 40 C.

below zero, to a temperature above 100 C. and stirring the mixture.

, 4. The process of formin a permanently plastical protective coating %or underground pipes and the like which comprises heating a mixture of plastic products having melting meltpoints between about 25 C. and 50 G.'to a temperature above 100 C. and stirring a finely ground mineral filler into the mixture.

5. The process of forming a permanently plastical protective coating or underground pipes and the like .which comprises heating a mixture of proto-parafiine, petroleum jelly and bitumen to a temperature above 100 C. and stirring the mixture.

6. The process of forming a permanently plastical protective coating for underground pipes and the like which comprises heating a mixture of proto-parafiine, petroleum jelly and bitumen to a temperature above 100 0., adding a mineral filler and stirring the mixture.

7. The process of forming a permanently plastical protective coating, or underground pipes and the like which comprises heating a mixture of. proto-paraifine having a melting point of above 50 C., petroleum ]elly having a meltin point above 20 C. and bitumen having a me ting point of about 30 C. to atemperature above 100 C. and stirring the mixture.

8. The process of forming a permanently plasticahprotective coating for underground pipes an the like which comprises heating a mixture of proto-parafline having a melting point of above 50 0., petroleum jelly having a melting point above 20 C. and bitumen having a melting point of about 30 C. in the proportions of about six to two to one to temperature, above 100 C. and stirring the mixture.

9. A ermanently plastical coating composition or underground pipes and the like comprising a mixture of p astic products having melting points between about 25 C. and 60 C. and bemg substantially free from moisture.

10. A permanently plastical coatin composition for underground pi es and t e like comprising a mixture of plastic products having melting points between about 25 C. and 60 0., said products being substantially free from moisture and containing a finely ground mineral filler.

11. A permanently plastical coating composition for underground pipes and the like comprising a mixture of proto-paraifine, petroleum jelly and bitumen substantially free from moisture.

12. A permanently plastical coating composition for underground pipes and the like comprising a mixture of proto-parafline,

petroleum jelly and bitumen in the proportions of about six to two to one substantially free from moisture. I Y

13. A permanently plastical coating-composition for underground pipes and the like comprising a mixture of proto-parafine, petroleum jelly and bitumen in the proportions of about six to two to one substan tially free from moisture and a larger amount of finely ground filler.

14. As an article of manufacture, the herein-described (protective bandage for the purposespecific comprising a base of flexible material coated with a permanently lastic non-hardening mixture of proto-para and soft bitumen, the mixture being substantially free from moisture.

w 15. As an article of manufacture, the here in-described protective bandage for the purpose specified, comprising a flexible base of fabric or paper coated with a non-hardening mixture of proto-paralfin, soft bitumen and a neutral substance or filler, the mixture being substantially free from moisture.

, 16. As an article of manufacture, a rotective bandage for the purpose specific comprising a base of textile fabric or of papercoated on both sides with a non-hardenin moisture-excluding mixture of residues 0 mineral oil distillation, such as proto-paraflin and petroleum jellies that constantly remain soft, soft bitumen and a filler such as porcelain clay.

17 As an article of manufacture, a rotective bandage for the purpose specific comprising a flexible base of fabric or paper coated on both sides with a mixture of lastic non-hardenin products having me tin points between a out 25 C. and 60 C. an substantially free from moisture.

18. As an article of manufacture, the herein-described rotective bandage for the purpose specified comprising a exible base or fabric or paper coated on both sides with-a non-hardening mixture of protoaraflin having a melting point of about 60 8, petroleum jelly having a melting point of about 25 (3.,

0 soft bitumen having a melting point of about 30 C. and a neutral substance or filler, the mixture being substantially free from moisture. v

. PAUL F. SCHADE. 

